The objective is to explore whether hospital participation with Medicare's Quality Improvement Organizations (QIOs) leads to better quality of care for Medicare beneficiaries. The QIO program is the largest federal initiative to improve the quality of care, and Medicare spends $200 million per year on the program. From the inception of Medicare, the federal government has been concerned about the quality of care provided to beneficiaries. Currently, Medicare contracts with QIOs to improve the quality of care. The QIOs collaborate with hospitals who participate on a voluntary basis. The QIOs' impact is measured using process indicators associated with clinical benefit. The proposed study is a retrospective pre-post controlled study that will compare the quality of care received by patients in hospitals that actively participate with the QIOs to the quality of care received by patients in hospitals that do not participate with the QIOs. The Delmarva and IPRO QIOs, which have responsibility for Maryland, the District of Columbia, and New York, have agreed to provide their data for this analysis. Approximately 50% of hospitals in these states participated with their QIOs to improve the quality of care. Quality will be assessed using 18 process indicators in 4 clinical areas (acute myocardial infarction, heart failure, stroke, pneumonia) in the inpatient setting. Baseline quality will be assessed using process indicator data collected in 1998-1999 from approximately 3500 medical records for each clinical area. Follow-up quality will be assessed on the same process indicators using data collected in 2000-2001, also from approximately 3500 medical records per clinical area. The hypothesis is that there will be a statistically significant (p<.05) difference in the increase in the proportion of patients receiving the quality processes in hospitals participating with the QIOs during the study period compared to the increase in proportion of patients in hospitals that did not participate. The analysis will control for hospital characteristics (bedsize, urban/rural status, for-profit/not-for-profit status, and teaching status) and patient characteristics (age, race, sex). This study is believed to be the first evaluation of the QIOs in multiple clinical areas using a control group. It evaluates an important government quality improvement effort and addresses the elderly, an Agency for Healthcare Research and Quality priority population. [unreadable] [unreadable]